Comparison of Nutritional Outcomes between Different Techniques of Intradialytic Amino Acid Infusion in Patients on Hemodialysis: A Randomized Controlled Trial

Background: Amino acid (AA) loss during catabolic process of dialysis deteriorates protein-energy status of hemodialysis (HD) patients. Therefore, AA replacement is crucial. This study aimed to compare intradialytic amino acid (IDAA) infusion between loading and continuous intradialytic infusion technique, which could provide better AA retention indicated by serum albumin levels. Methods: This randomized controlled trial (TCTR 20230401003) involved high flux membrane HD patients with a serum albumin level between 3.5 and 3.9 g/dL. Those were randomly assigned in a 1:1 ratio to loading group that started with 50% glucose 100 ml infused for 20 minutes, followed by AA 200 ml infused for 20 minutes at the last hour of the session, or continuous group that administered 50% glucose 100 ml after starting HD followed by AA 200 ml until the end of HD, with a total duration of approximately 3.5 hours. The primary outcome was the difference of albumin levels after 3 months of IDAA supplementation between the two techniques. Results: A total of 48 HD patients completed the study (n=24 per group). The mean age was 68.9±12.8 years with average MIS of 6.4±2.8 points. Baseline characteristics were not different between groups. Despite comparable energy and protein intake, serum albumin levels were significantly increased in continuous group after 3 months of IDAA (from 3.75±0.14 to 3.94±0.22 g/dL, p<0.01) whereas it was still unchanged in the loading group (from 3.76±0.11 to 3.88±0.36 g/dL, p=0.21). The average total AA losses in dialysate were not significantly different between the continuous and loading groups (6.7±1.4 VS 7.8±3.7 g/session, respectively, p=0.17). Both plasma essential (p=0.59) and non-essential AA levels (p=0.66) between groups were also similar at the end of study. Muscle mass, strength, and gait speed did not differ between both groups (all p>0.05). Neither volume overload nor hyperglycemia requiring additional insulin therapy was found throughout the study. Conclusion: IDAA supplementation using continuous infusion during dialysis session appears to be superior to a loading technique in terms of an improvement in serum albumin levels, a survival surrogate among HD patients. The impact of IDAA on clinical outcomes may require larger scale with longer period of study. Funding: Private Foundation Support